1. Technical Field
The present invention relates to a physical quantity detection circuit, a physical quantity detection device, an electronic apparatus and a moving object.
2. Related Art
Nowadays, physical quantity detection devices, such as an acceleration sensor that detects an acceleration and a gyro sensor that detects an angular velocity, which are capable of detecting various physical quantities are being widely used in various systems and electronic apparatuses. In recent years, physical quantity detection devices have been mounted on automobiles and the like, and have required high detection accuracy and high reliability even under noisy environments.
The physical quantity detection device that outputs detection information of a physical quantity as a digital signal outputs a digital signal having high noise resistance, thereby allowing high reliability to be secured even under noisy environments. For example, JP-A-2009-229447 proposes a physical quantity measuring device including a detection circuit that detects an analog signal which is output from a vibrator by a detector circuit, and then converts the detected signal into a digital signal by an A/D converter to output the converted signal. In the physical quantity measuring device disclosed in JP-A-2009-229447, it is considered that the detection circuit is constituted by an analog circuit and is replaced by a digital circuit in order to improve detection accuracy. For example, JP-A-2007-327943 discloses that in a detection device that includes a detection circuit having a filter portion, a discrete-time filter (SCF) constituting the filter portion is able to be replaced by a digital filter.
However, there is a problem in terms of cost, because when a detection circuit of an existing physical quantity detection device is simply replaced by a digital circuit, the number of adders or multipliers increases and thus a circuit scale increases.